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   1 /*
   2  * linux/fs/lockd/svc.c
   3  *
   4  * This is the central lockd service.
   5  *
   6  * FIXME: Separate the lockd NFS server functionality from the lockd NFS
   7  *        client functionality. Oh why didn't Sun create two separate
   8  *        services in the first place?
   9  *
  10  * Authors:     Olaf Kirch (okir@monad.swb.de)
  11  *
  12  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/sysctl.h>
  18 #include <linux/moduleparam.h>
  19
  20 #include <linux/sched.h>
  21 #include <linux/errno.h>
  22 #include <linux/in.h>
  23 #include <linux/uio.h>
  24 #include <linux/slab.h>
  25 #include <linux/smp.h>
  26 #include <linux/smp_lock.h>
  27 #include <linux/mutex.h>
  28 #include <linux/kthread.h>
  29 #include <linux/freezer.h>
  30
  31 #include <linux/sunrpc/types.h>
  32 #include <linux/sunrpc/stats.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/svc.h>
  35 #include <linux/sunrpc/svcsock.h>
  36 #include <net/ip.h>
  37 #include <linux/lockd/lockd.h>
  38 #include <linux/lockd/sm_inter.h>
  39 #include <linux/nfs.h>
  40
  41 #define NLMDBG_FACILITY         NLMDBG_SVC
  42 #define LOCKD_BUFSIZE           (1024 + NLMSVC_XDRSIZE)
  43 #define ALLOWED_SIGS            (sigmask(SIGKILL))
  44
  45 static struct svc_program       nlmsvc_program;
  46
  47 struct nlmsvc_binding *         nlmsvc_ops;
  48 EXPORT_SYMBOL(nlmsvc_ops);
  49
  50 static DEFINE_MUTEX(nlmsvc_mutex);
  51 static unsigned int             nlmsvc_users;
  52 static struct task_struct       *nlmsvc_task;
  53 static struct svc_rqst          *nlmsvc_rqst;
  54 int                             nlmsvc_grace_period;
  55 unsigned long                   nlmsvc_timeout;
  56
  57 /*
  58  * These can be set at insmod time (useful for NFS as root filesystem),
  59  * and also changed through the sysctl interface.  -- Jamie Lokier, Aug 2003
  60  */
  61 static unsigned long            nlm_grace_period;
  62 static unsigned long            nlm_timeout = LOCKD_DFLT_TIMEO;
  63 static int                      nlm_udpport, nlm_tcpport;
  64 int                             nsm_use_hostnames = 0;
  65
  66 /*
  67  * Constants needed for the sysctl interface.
  68  */
  69 static const unsigned long      nlm_grace_period_min = 0;
  70 static const unsigned long      nlm_grace_period_max = 240;
  71 static const unsigned long      nlm_timeout_min = 3;
  72 static const unsigned long      nlm_timeout_max = 20;
  73 static const int                nlm_port_min = 0, nlm_port_max = 65535;
  74
  75 #ifdef CONFIG_SYSCTL
  76 static struct ctl_table_header * nlm_sysctl_table;
  77 #endif
  78
  79 static unsigned long get_lockd_grace_period(void)
  80 {
  81         /* Note: nlm_timeout should always be nonzero */
  82         if (nlm_grace_period)
  83                 return roundup(nlm_grace_period, nlm_timeout) * HZ;
  84         else
  85                 return nlm_timeout * 5 * HZ;
  86 }
  87
  88 unsigned long get_nfs_grace_period(void)
  89 {
  90         unsigned long lockdgrace = get_lockd_grace_period();
  91         unsigned long nfsdgrace = 0;
  92
  93         if (nlmsvc_ops)
  94                 nfsdgrace = nlmsvc_ops->get_grace_period();
  95
  96         return max(lockdgrace, nfsdgrace);
  97 }
  98 EXPORT_SYMBOL(get_nfs_grace_period);
  99
 100 static unsigned long set_grace_period(void)
 101 {
 102         nlmsvc_grace_period = 1;
 103         return get_nfs_grace_period() + jiffies;
 104 }
 105
 106 static inline void clear_grace_period(void)
 107 {
 108         nlmsvc_grace_period = 0;
 109 }
 110
 111 /*
 112  * This is the lockd kernel thread
 113  */
 114 static int
 115 lockd(void *vrqstp)
 116 {
 117         int             err = 0, preverr = 0;
 118         struct svc_rqst *rqstp = vrqstp;
 119         unsigned long grace_period_expire;
 120
 121         /* try_to_freeze() is called from svc_recv() */
 122         set_freezable();
 123
 124         /* Allow SIGKILL to tell lockd to drop all of its locks */
 125         allow_signal(SIGKILL);
 126
 127         dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 128
 129         /*
 130          * FIXME: it would be nice if lockd didn't spend its entire life
 131          * running under the BKL. At the very least, it would be good to
 132          * have someone clarify what it's intended to protect here. I've
 133          * seen some handwavy posts about posix locking needing to be
 134          * done under the BKL, but it's far from clear.
 135          */
 136         lock_kernel();
 137
 138         if (!nlm_timeout)
 139                 nlm_timeout = LOCKD_DFLT_TIMEO;
 140         nlmsvc_timeout = nlm_timeout * HZ;
 141
 142         grace_period_expire = set_grace_period();
 143
 144         /*
 145          * The main request loop. We don't terminate until the last
 146          * NFS mount or NFS daemon has gone away.
 147          */
 148         while (!kthread_should_stop()) {
 149                 long timeout = MAX_SCHEDULE_TIMEOUT;
 150                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 151
 152                 if (signalled()) {
 153                         flush_signals(current);
 154                         if (nlmsvc_ops) {
 155                                 nlmsvc_invalidate_all();
 156                                 grace_period_expire = set_grace_period();
 157                         }
 158                         continue;
 159                 }
 160
 161                 timeout = nlmsvc_retry_blocked();
 162
 163                 if (time_before(grace_period_expire, jiffies))
 164                         clear_grace_period();
 165
 166                 /*
 167                  * Find a socket with data available and call its
 168                  * recvfrom routine.
 169                  */
 170                 err = svc_recv(rqstp, timeout);
 171                 if (err == -EAGAIN || err == -EINTR) {
 172                         preverr = err;
 173                         continue;
 174                 }
 175                 if (err < 0) {
 176                         if (err != preverr) {
 177                                 printk(KERN_WARNING "%s: unexpected error "
 178                                         "from svc_recv (%d)\n", __func__, err);
 179                                 preverr = err;
 180                         }
 181                         schedule_timeout_interruptible(HZ);
 182                         continue;
 183                 }
 184                 preverr = err;
 185
 186                 dprintk("lockd: request from %s\n",
 187                                 svc_print_addr(rqstp, buf, sizeof(buf)));
 188
 189                 svc_process(rqstp);
 190         }
 191         flush_signals(current);
 192         if (nlmsvc_ops)
 193                 nlmsvc_invalidate_all();
 194         nlm_shutdown_hosts();
 195         unlock_kernel();
 196         return 0;
 197 }
 198
 199 /*
 200  * Make any sockets that are needed but not present.
 201  * If nlm_udpport or nlm_tcpport were set as module
 202  * options, make those sockets unconditionally
 203  */
 204 static int make_socks(struct svc_serv *serv, int proto)
 205 {
 206         static int warned;
 207         struct svc_xprt *xprt;
 208         int err = 0;
 209
 210         if (proto == IPPROTO_UDP || nlm_udpport) {
 211                 xprt = svc_find_xprt(serv, "udp", 0, 0);
 212                 if (!xprt)
 213                         err = svc_create_xprt(serv, "udp", nlm_udpport,
 214                                               SVC_SOCK_DEFAULTS);
 215                 else
 216                         svc_xprt_put(xprt);
 217         }
 218         if (err >= 0 && (proto == IPPROTO_TCP || nlm_tcpport)) {
 219                 xprt = svc_find_xprt(serv, "tcp", 0, 0);
 220                 if (!xprt)
 221                         err = svc_create_xprt(serv, "tcp", nlm_tcpport,
 222                                               SVC_SOCK_DEFAULTS);
 223                 else
 224                         svc_xprt_put(xprt);
 225         }
 226         if (err >= 0) {
 227                 warned = 0;
 228                 err = 0;
 229         } else if (warned++ == 0)
 230                 printk(KERN_WARNING
 231                        "lockd_up: makesock failed, error=%d\n", err);
 232         return err;
 233 }
 234
 235 /*
 236  * Bring up the lockd process if it's not already up.
 237  */
 238 int
 239 lockd_up(int proto) /* Maybe add a 'family' option when IPv6 is supported ?? */
 240 {
 241         struct svc_serv *serv;
 242         int             error = 0;
 243
 244         mutex_lock(&nlmsvc_mutex);
 245         /*
 246          * Check whether we're already up and running.
 247          */
 248         if (nlmsvc_rqst) {
 249                 if (proto)
 250                         error = make_socks(nlmsvc_rqst->rq_server, proto);
 251                 goto out;
 252         }
 253
 254         /*
 255          * Sanity check: if there's no pid,
 256          * we should be the first user ...
 257          */
 258         if (nlmsvc_users)
 259                 printk(KERN_WARNING
 260                         "lockd_up: no pid, %d users??\n", nlmsvc_users);
 261
 262         error = -ENOMEM;
 263         serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, AF_INET, NULL);
 264         if (!serv) {
 265                 printk(KERN_WARNING "lockd_up: create service failed\n");
 266                 goto out;
 267         }
 268
 269         if ((error = make_socks(serv, proto)) < 0)
 270                 goto destroy_and_out;
 271
 272         /*
 273          * Create the kernel thread and wait for it to start.
 274          */
 275         nlmsvc_rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
 276         if (IS_ERR(nlmsvc_rqst)) {
 277                 error = PTR_ERR(nlmsvc_rqst);
 278                 nlmsvc_rqst = NULL;
 279                 printk(KERN_WARNING
 280                         "lockd_up: svc_rqst allocation failed, error=%d\n",
 281                         error);
 282                 goto destroy_and_out;
 283         }
 284
 285         svc_sock_update_bufs(serv);
 286
 287         nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, serv->sv_name);
 288         if (IS_ERR(nlmsvc_task)) {
 289                 error = PTR_ERR(nlmsvc_task);
 290                 svc_exit_thread(nlmsvc_rqst);
 291                 nlmsvc_task = NULL;
 292                 nlmsvc_rqst = NULL;
 293                 printk(KERN_WARNING
 294                         "lockd_up: kthread_run failed, error=%d\n", error);
 295                 goto destroy_and_out;
 296         }
 297
 298         /*
 299          * Note: svc_serv structures have an initial use count of 1,
 300          * so we exit through here on both success and failure.
 301          */
 302 destroy_and_out:
 303         svc_destroy(serv);
 304 out:
 305         if (!error)
 306                 nlmsvc_users++;
 307         mutex_unlock(&nlmsvc_mutex);
 308         return error;
 309 }
 310 EXPORT_SYMBOL(lockd_up);
 311
 312 /*
 313  * Decrement the user count and bring down lockd if we're the last.
 314  */
 315 void
 316 lockd_down(void)
 317 {
 318         mutex_lock(&nlmsvc_mutex);
 319         if (nlmsvc_users) {
 320                 if (--nlmsvc_users)
 321                         goto out;
 322         } else {
 323                 printk(KERN_ERR "lockd_down: no users! task=%p\n",
 324                         nlmsvc_task);
 325                 BUG();
 326         }
 327
 328         if (!nlmsvc_task) {
 329                 printk(KERN_ERR "lockd_down: no lockd running.\n");
 330                 BUG();
 331         }
 332         kthread_stop(nlmsvc_task);
 333         svc_exit_thread(nlmsvc_rqst);
 334         nlmsvc_task = NULL;
 335         nlmsvc_rqst = NULL;
 336 out:
 337         mutex_unlock(&nlmsvc_mutex);
 338 }
 339 EXPORT_SYMBOL(lockd_down);
 340
 341 #ifdef CONFIG_SYSCTL
 342
 343 /*
 344  * Sysctl parameters (same as module parameters, different interface).
 345  */
 346
 347 static ctl_table nlm_sysctls[] = {
 348         {
 349                 .ctl_name       = CTL_UNNUMBERED,
 350                 .procname       = "nlm_grace_period",
 351                 .data           = &nlm_grace_period,
 352                 .maxlen         = sizeof(unsigned long),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_doulongvec_minmax,
 355                 .extra1         = (unsigned long *) &nlm_grace_period_min,
 356                 .extra2         = (unsigned long *) &nlm_grace_period_max,
 357         },
 358         {
 359                 .ctl_name       = CTL_UNNUMBERED,
 360                 .procname       = "nlm_timeout",
 361                 .data           = &nlm_timeout,
 362                 .maxlen         = sizeof(unsigned long),
 363                 .mode           = 0644,
 364                 .proc_handler   = &proc_doulongvec_minmax,
 365                 .extra1         = (unsigned long *) &nlm_timeout_min,
 366                 .extra2         = (unsigned long *) &nlm_timeout_max,
 367         },
 368         {
 369                 .ctl_name       = CTL_UNNUMBERED,
 370                 .procname       = "nlm_udpport",
 371                 .data           = &nlm_udpport,
 372                 .maxlen         = sizeof(int),
 373                 .mode           = 0644,
 374                 .proc_handler   = &proc_dointvec_minmax,
 375                 .extra1         = (int *) &nlm_port_min,
 376                 .extra2         = (int *) &nlm_port_max,
 377         },
 378         {
 379                 .ctl_name       = CTL_UNNUMBERED,
 380                 .procname       = "nlm_tcpport",
 381                 .data           = &nlm_tcpport,
 382                 .maxlen         = sizeof(int),
 383                 .mode           = 0644,
 384                 .proc_handler   = &proc_dointvec_minmax,
 385                 .extra1         = (int *) &nlm_port_min,
 386                 .extra2         = (int *) &nlm_port_max,
 387         },
 388         {
 389                 .ctl_name       = CTL_UNNUMBERED,
 390                 .procname       = "nsm_use_hostnames",
 391                 .data           = &nsm_use_hostnames,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396         {
 397                 .ctl_name       = CTL_UNNUMBERED,
 398                 .procname       = "nsm_local_state",
 399                 .data           = &nsm_local_state,
 400                 .maxlen         = sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = &proc_dointvec,
 403         },
 404         { .ctl_name = 0 }
 405 };
 406
 407 static ctl_table nlm_sysctl_dir[] = {
 408         {
 409                 .ctl_name       = CTL_UNNUMBERED,
 410                 .procname       = "nfs",
 411                 .mode           = 0555,
 412                 .child          = nlm_sysctls,
 413         },
 414         { .ctl_name = 0 }
 415 };
 416
 417 static ctl_table nlm_sysctl_root[] = {
 418         {
 419                 .ctl_name       = CTL_FS,
 420                 .procname       = "fs",
 421                 .mode           = 0555,
 422                 .child          = nlm_sysctl_dir,
 423         },
 424         { .ctl_name = 0 }
 425 };
 426
 427 #endif  /* CONFIG_SYSCTL */
 428
 429 /*
 430  * Module (and sysfs) parameters.
 431  */
 432
 433 #define param_set_min_max(name, type, which_strtol, min, max)           \
 434 static int param_set_##name(const char *val, struct kernel_param *kp)   \
 435 {                                                                       \
 436         char *endp;                                                     \
 437         __typeof__(type) num = which_strtol(val, &endp, 0);             \
 438         if (endp == val || *endp || num < (min) || num > (max))         \
 439                 return -EINVAL;                                         \
 440         *((int *) kp->arg) = num;                                       \
 441         return 0;                                                       \
 442 }
 443
 444 static inline int is_callback(u32 proc)
 445 {
 446         return proc == NLMPROC_GRANTED
 447                 || proc == NLMPROC_GRANTED_MSG
 448                 || proc == NLMPROC_TEST_RES
 449                 || proc == NLMPROC_LOCK_RES
 450                 || proc == NLMPROC_CANCEL_RES
 451                 || proc == NLMPROC_UNLOCK_RES
 452                 || proc == NLMPROC_NSM_NOTIFY;
 453 }
 454
 455
 456 static int lockd_authenticate(struct svc_rqst *rqstp)
 457 {
 458         rqstp->rq_client = NULL;
 459         switch (rqstp->rq_authop->flavour) {
 460                 case RPC_AUTH_NULL:
 461                 case RPC_AUTH_UNIX:
 462                         if (rqstp->rq_proc == 0)
 463                                 return SVC_OK;
 464                         if (is_callback(rqstp->rq_proc)) {
 465                                 /* Leave it to individual procedures to
 466                                  * call nlmsvc_lookup_host(rqstp)
 467                                  */
 468                                 return SVC_OK;
 469                         }
 470                         return svc_set_client(rqstp);
 471         }
 472         return SVC_DENIED;
 473 }
 474
 475
 476 param_set_min_max(port, int, simple_strtol, 0, 65535)
 477 param_set_min_max(grace_period, unsigned long, simple_strtoul,
 478                   nlm_grace_period_min, nlm_grace_period_max)
 479 param_set_min_max(timeout, unsigned long, simple_strtoul,
 480                   nlm_timeout_min, nlm_timeout_max)
 481
 482 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");
 483 MODULE_DESCRIPTION("NFS file locking service version " LOCKD_VERSION ".");
 484 MODULE_LICENSE("GPL");
 485
 486 module_param_call(nlm_grace_period, param_set_grace_period, param_get_ulong,
 487                   &nlm_grace_period, 0644);
 488 module_param_call(nlm_timeout, param_set_timeout, param_get_ulong,
 489                   &nlm_timeout, 0644);
 490 module_param_call(nlm_udpport, param_set_port, param_get_int,
 491                   &nlm_udpport, 0644);
 492 module_param_call(nlm_tcpport, param_set_port, param_get_int,
 493                   &nlm_tcpport, 0644);
 494 module_param(nsm_use_hostnames, bool, 0644);
 495
 496 /*
 497  * Initialising and terminating the module.
 498  */
 499
 500 static int __init init_nlm(void)
 501 {
 502 #ifdef CONFIG_SYSCTL
 503         nlm_sysctl_table = register_sysctl_table(nlm_sysctl_root);
 504         return nlm_sysctl_table ? 0 : -ENOMEM;
 505 #else
 506         return 0;
 507 #endif
 508 }
 509
 510 static void __exit exit_nlm(void)
 511 {
 512         /* FIXME: delete all NLM clients */
 513         nlm_shutdown_hosts();
 514 #ifdef CONFIG_SYSCTL
 515         unregister_sysctl_table(nlm_sysctl_table);
 516 #endif
 517 }
 518
 519 module_init(init_nlm);
 520 module_exit(exit_nlm);
 521
 522 /*
 523  * Define NLM program and procedures
 524  */
 525 static struct svc_version       nlmsvc_version1 = {
 526                 .vs_vers        = 1,
 527                 .vs_nproc       = 17,
 528                 .vs_proc        = nlmsvc_procedures,
 529                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 530 };
 531 static struct svc_version       nlmsvc_version3 = {
 532                 .vs_vers        = 3,
 533                 .vs_nproc       = 24,
 534                 .vs_proc        = nlmsvc_procedures,
 535                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 536 };
 537 #ifdef CONFIG_LOCKD_V4
 538 static struct svc_version       nlmsvc_version4 = {
 539                 .vs_vers        = 4,
 540                 .vs_nproc       = 24,
 541                 .vs_proc        = nlmsvc_procedures4,
 542                 .vs_xdrsize     = NLMSVC_XDRSIZE,
 543 };
 544 #endif
 545 static struct svc_version *     nlmsvc_version[] = {
 546         [1] = &nlmsvc_version1,
 547         [3] = &nlmsvc_version3,
 548 #ifdef CONFIG_LOCKD_V4
 549         [4] = &nlmsvc_version4,
 550 #endif
 551 };
 552
 553 static struct svc_stat          nlmsvc_stats;
 554
 555 #define NLM_NRVERS      ARRAY_SIZE(nlmsvc_version)
 556 static struct svc_program       nlmsvc_program = {
 557         .pg_prog                = NLM_PROGRAM,          /* program number */
 558         .pg_nvers               = NLM_NRVERS,           /* number of entries in nlmsvc_version */
 559         .pg_vers                = nlmsvc_version,       /* version table */
 560         .pg_name                = "lockd",              /* service name */
 561         .pg_class               = "nfsd",               /* share authentication with nfsd */
 562         .pg_stats               = &nlmsvc_stats,        /* stats table */
 563         .pg_authenticate = &lockd_authenticate  /* export authentication */
 564 };